1. Field of the Invention
The present invention relates to a variable color lighting system, and more particularly to a spotlight or floodlight system in which the color of the light may be continuously varied.
2. Description of the Prior Art
The use of colored lights for displays, theatrical productions, and similar activities is necessary in which the color of the light can be varied from time to time. In the prior art, such variations have normally been provided by using separate spotlights or floodlights for each color and fading the units in and one out. Other methods include the use of colored filters, such as gelatin and the like, which are sequentially placed in front of a white light source. However, these techniques permit changing of color only in discrete steps and is not easily adaptable to provide a continuous color variation.
It is known, for relatively small light sources such as for photographic enlargement of color negative films, to provide continuously variable colored light. In U.S. Pat. No. 3,818,216 to Larraburu, a broad spectrum tungsten lamp has its intensity manually controlled. A complex arrangement of dichroic mirrors is utilized which separates the spectrum of the lamp into three colors. Each color has an individual attenuation device to control the intensity of the individual colors. The colors are then recombined through a lenticular lens system to provide a uniform output beam in which the color content and intensity can be manually controlled. Reynolds, in U.S. Pat. No. 3,825,335, teaches a system having three different colored light sources and forms bundles of fiber optic transmission cables having individual fibers attached to each of the colors for combining the three colors. Thus, the output at the end of a fiber bundle will produce an additive mixture of the colors. By individually adjusting the intensity of each colored light source, the composite color can be varied. A computer-controlled lighting system which includes variable color and intensity is taught in U.S. Pat. No. 4,392,187 to Bornhorst. The system uses four dichroic filters which are pivoted in various combinations so as to transmit a preselected color.
None of this known art teaches a spotlight or floodlight device suitable for theatrical use which is easily controlled in intensity and whose spectrum may be controlled continuously over the visible color spectrum.